These wonderful pendants were thought to be accessories made to bring good fortune to their wearer. Ancient Romans believed that wearing trinkets like these disks would not only provide them with luck but also ward off the evil eye. Iconographies were extremely differentiated, including apotropaic symbols, images of deities and animals. The Medusa was a mythological female creature with hair made of living venomous snakes. It was said that gazing into her eyes would turn you to stone. Medusa was beheaded by the greek hero Perseus, who managed to defeat her by looking into the reflection on his shield, avoiding petrification by making eye-contact.
To find out more about Roman glass please see our relevant blog posts: Ancient Glass and Collecting Roman Glass.